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Java gridbaglayout using scrollpane with draggable jpanel

Im using a gridbaglayout on a jpanel with a scrollpane, all that works fine. Later in my code i add another jpanel using the constraints(x,y) to the same panel on top of everything else thats already there using the index, this also works fine. This added jpanel uses a listener to let me drag the panel around which also works but my problem is when i scroll or resize the jframe it puts the jpanel back where it was before i dragged it. Why?

This added jpanel uses a listener to let me drag the panel around which also works but my problem is when i scroll or resize the jframe it puts the jpanel back where it was before i dragged it. Why?
Because you are using a layout manager. When the frame is resized the layout manager is invoked and components are assigned a size/location based on the rules of the layout manager.
Check out the Drag Layout. It will allow you to drag components around a panel without resetting the location of the components.

How to make a JFrame scrollable?

I would like to scroll through the contents of my JFrame up and down, preferably with a scroll bar. I don't want to wrap the contents inside a JPanel or JScrollPane, because this causes some visual glitches with my application.
Any idea on how to do this?

JScrollPane would be the easiest way; you say there are glitches, but that probably indicates a problem in your code that will still be a problem even without using a JScrollPane.
If you're absolutely set on not using a JScrollPane, you should create a JPanel using BorderLayout, add a JPanel (call it 'center') with BorderLayout.CENTER and layout set to null. Add your content within 'center', and add another JScrollBar to BorderLayout.EAST, add an AdjustmentListener to the JScrollBar. When the adjustmentListener triggers, you need to move your content (Component.setLocation(...)) that's in center to the relative y offset of the JScrollBar and call repaint on 'center'

How to force-refresh/repaint a JScrollPane?

I am adding lots of components (JPanels, JLabels etc.) into a JScrollPane programagically at the start of my program based on some stuff from a database.
It seems that this procedure is too fast for the GUI(?), so the JScrollPane does not always update correctly, i.e the scroll bars are not visible even though the inner JPanel is bigger than the visible area.
Resizing the Window (JFrame) fixes the problem, as I assume Java is re-printing the components when they are resized.
As a test, I have added a debug-button that I can click after the startup of the program has finished. I am trying to force the JScrollPane to "refresh" itself.
I have tried doing:
scrollpane.repaint();
scrollpane.validate();
scrollpane.revalidate();
None of them seems to work. However, if I change the border (or any other layout related to the JScrollPane), it refreshes correctly.
scrollpane.setBorder(new LineBorder(Color.RED));
So I basically have 2 questions.
What is the command for forcing the scrollpane to "refresh"? Obviously it is doing some kind of "repaint" thing when I am adding the border. How can I run that only?
Is there a way of "pausing" the printing of components as they are added and resume it again after I added all the wanted components? As it is now, I basically "see" the components being added on the screen (even though it is really fast). It would be better if I can add all the components I want and THEN tell the program to print it to the screen/JFrame.

The basic code for adding components to a visible panel is:
panel.add(...);
panel.add(...);
panel.revalidate();
panel.repaint();
Adding a component does nothing because the component still has a zero size so there is nothing to paint. When you invoke the revalidate() method the layout manager gets invoked so components will now have a location/size. The repaint() will then paint the components. The revalidate() will also cause the scrollbars to show when required. This of course assumes you are using layout managers.
The components are added to the panel so you invoke the methods on the panel, not the scrollpane.

In my case only
frame.pack();
helped to get the scrollbars on the JScrollPane, when the enclosed JPanel was resized dynamically.

JPanel adjust to JScrollpane and children

I'm trying to make a ToDoManager in java. For now I have about what I want it to be for a basic version. But I'm having a problem with the size of a panel.
I have a main JFrame. This contains a JPanel, say jPanel1.
jPanel1 has 2 buttons (add and remove) and another JPanel (say jPanel2).
jPanel2 contains a JScrollPane, which contains a modified version of JTable.
The thing I want is to tell the JTable to stretch out, so i can view everything in the JTable, and then tell the JScrollPane and jPanel2 to "Pack", or resize, so the JTable is completely vissable (if not possible the JScrollPane should do its work and draw the scrollbars).
This is what I have got at the moment:
So maybe you can see 2 problems:
1) The horizontal scroll bar does not appear. (But I did set the scroll bar: HORIZONTAL_AS_NEEDED)
2) I did not set any preferred size for the main JFrame, nor for the jPanel1, but it packs always as the same size. So I would like to stretch the jPanel2 to the full JTable, and if that would exceed the screen size, draw the scroll bars.

Using another layout manager, it's a lot easier to comprehend the usage of the JPanels and this concludes the problem.

How to prevent JScrollPane from automatically scrolling down?

I am using a JScrollPane which contains inside it a JTextArea. The problem is when the JTextArea is populated with a lot of text, the JScrollPane automatically scrolls down. What property should I set on the JScrollPane to avoid this automatic scrolling down? Thanks.

If the JScrollPane is decorating a text component, it will automatically scroll to the bottom, but after it loads calling setCaretPosition(0) on your text component will cause it to scroll to the top.
However, if it's not a text component, you can also alter the viewport like this:
scrollPane.getViewport().setViewPosition(new Point(0,0));